Prerequisites

here we go

1. Have a clean usb partition and partition it (mfdisk -c /dev/sda) as sda1 (the first usb you put into your terastation is sda). It should have about 371MB. Format it xfs or ext2. Touch the file INIT-SYSBACKUP and reboot. (!!: if it is drive, it is automounted to /mnt/usbdisk1, if it is a stick it is not automounted - I used a stick)

2. After booting your system has been copied to your stick. If you touch the file /etc/HD-HTGL-EM, then your system is booted from sda1, bypassing other checks. To have Complete Functionality , some other corrections are neccessary. (See below)